The present invention relates to an interconnection system between an image pickup device such as a color television camera and a recording device such as a video tape recorder.
A color television camera and a video tape recorder are interconnected with a suitable cable so that the video, audio and operation control signal may be transmitted from the camera to the recorder and the reproduced video signal may be transmitted from the recorder to the camera so that one can review the reproduced images on an electronic viewfinder.
So far the multicore cables have been used in interconnecting the cameras and the recorders. The use of such cables has some problems to be described below. First since the cable is very heavy, operability is poor; that is, handling of the television camera is inconvenient. Secondly, the multicore cables are in general large in diameter so that a large space is needed for storage and it is inconvenient to store or take out a cable. Thirdly, special connectors and special multicore cables must be used because of the transmission of various signals such as the video, audio and operation control signals. As a result, they are expensive.
In order to overcome the above-described problems, the use of wireless transmission of signals between a television camera and a video tape recorder might be considered so that the interconnection cables could be eliminated. However, because of the communications laws, only a very weak output is obtained so that S/N ratio is low. In addition, the image quality would be degraded by external interference. As a result, the wireless transmission could be used in practice only under specially favourable conditions. Thus, as a countermeasure, the use of only one signal line is considered. To this end, the standard television modulation of the audio and video signals may be proposed. However, a RF converter must be mounted on a television camera while a tuner, an intermediate frequency (IF) circuit, a video demodulator, an audio demodulator and so on must be added to a video tape recorder so that the interconnection system would become very complex in construction and very expensive.